The quartz crystal is one of the best studied and most behaved of crystals. Its elastic, piezoelectric and temperature properties are well known, and the sets of material constants are very accurate. Hence, numerical analyses of the frequency and frequency-temperature characteristics of quartz resonators have been remarkably accurate. Engineers with years of experience and experimentation usually design stable quartz crystal resonators. However, there is little experience in designing a stable quartz MEMS thickness shear resonator in the frequency range of 3 GHz because the existing conventional resonators will not operate in that frequency range. A 3 GHz resonator will have an electrode to plate thickness ratio of more than 27% and such a high electrode to plate thickness ratio will degrade the temperature behavior, quality, or A, aging and noise of the resonator.
Thus, there has been a long-felt need for a stable quartz resonator in the frequency range of 3 GHz with an electrode to plate thickness ratio of less than 27% that does not degrade the temperature behavior, Q, aging and noise of the resonator. To satisfy the long-felt need for a 3 GHz stable quartz resonator without suffering from the disadvantages, shortcomings and limitations of prior art techniques and devices, it is necessary to provide new electrode and plate structures. The present invention provides double-sided, single-sided and ring electrode mesa resonators that operate in the difficult 3 GHZ frequency with an advantageous and innovative electrode-free resonator area that separates the electrodes from the resonator structure so that the resonator structure serves as an energy-trapping area, without suffering from the disadvantages, shortcomings and limitations of prior art techniques and devices.